Navegando por Autor "GOMES, Andreza de Lourdes Souza"

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Acesso aberto (Open Access)
Estresse oxidativo de aves em clareiras naturais e sub-bosque na região Amazônica
(Universidade Federal do Pará, 2013) GOMES, Andreza de Lourdes Souza; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Background: (Oxidative stress of birds in natural gaps and understory sites in the Amazon region). Studies that provide information about the distribution of birds in different phases of forest mosaic are essential for understanding the maintenance of biodiversity, since natural gaps play a central role on the structure and dynamics of tropical forest. Objectives: (a) to determine and compare the abundance and richness of frugivorous birds between the natural gap and understory habitats; (b) verify and associate the abundance of frugivorous birds with the availability of fruits in both areas; (c) to investigate the echophysiological interactions between the oxidative stress and the distribution of specimens of Dixiphia pipra and Willisornis poecilinotus, to determine which factors account for the variance of biomarkers of oxidative stress in these species. Methods: This study was carried out from November 2010 to October 2011 in terra firme forest sites at the National Forest of Caxiuanã, Melgaço, Pará, Brazil. Two different understory forest habitats were selected for sampling on the basis of physiognomies: natural tree fall gap and undisturbed forest. Twelve (12) sites were selected (6 natural gaps and 6 undisturbed continuous forests). In each site, groups of 10 mist nets were set at ground level which remained open from 6:00am to 2:00pm for two consecutive days, totaling six days each month. This procedure lasted for 12 months and the sampling effort totaled 23,040 mist net hours. All specimens captured were identified, marked with metal rings and kept in cotton bags. We collected blood, feces and regurgitation samples to determine the biomarkers of oxidative stress and the composition of the diet. The relationship between thiobarbituric acid reactive substances and the total antioxidant capacity was used as an index of oxidative stress. The vegetation structure was determined based on transects along the mist nets; the plants bearing fruits were identified and the total antioxidant capacity was determined in each plant. Results: During the period of the study 347 specimens of 21 species were sampled. The assemblage of frugivorous birds in natural gap is distinct from that of undisturbed forest sites. The species responsible for dissimilarity were Dixiphia pipra, Pipra rubrocapilla and Turdus albicollis. The richness of birds was similar in both sites, but the availability of fruits and the total capture index were higher in natural gaps. The primary frugivores (those whose feces or regurgitation always showed fruit pulp or seeds) occurred mainly in natural gaps, where the most abundant species was Dixiphia pipra. In addition, Pipra rubrocapilla was the most abundant species in undisturbed sites. Thirty-six (36) species of plants bearing fruits were recorded, and the abundance of frugivorous birds was significantly correlated with the number of plants bearing fruits in natural gaps, where the most common species of plants were: Psychotria colorata and Psychotria iodotricha. On the other hand, Faramea anisocalyx and Virola surinamensis were the most common species in undisturbed sites. The variation of biomarkers of oxidative stress in specimens presenting lek behavior varied with gender and to the site of sampling. In natural gaps, the adult males of Dixiphia pipra showed higher levels of oxidative stress. The high metabolic rate resulting of flight effort to avoid predators, courtship behavior to the female and territory defense, can increase the production of pro-oxidant compounds. However, the ingestion of fruits with high content of antioxidant compounds by male can minimize the deleterious effects of oxidative stress. The variance of oxidative stress of species that do not have organization in leks was associated only with the site of sampling. The specimens sampling in natural gaps showed higher levels of oxidative stress. This can be due to the increase in metabolic rate to avoid predators as well as new flight strategies for foraging.
Acesso aberto (Open Access)
A first evaluation on the use of Ardea albus feathers as bioindicators of mercury burden in Amazonian ecosystems
(Instituto Nacional de Pesquisas da Amazônia, 2009) GOMES, Andreza de Lourdes Souza; VIEIRA, José Luiz Fernandes; PINHEIRO, Maria da Conceição Nascimento; MARCELIANO, Maria Luiza Videira
We evaluated in this study the total mercury concentration in feathers of Ardea albus collected in a colony located in the city of Belem-PA, Brazil in a prospective trial for its use as bioindicators of mercury burden in Amazonia ecosystems. An Atomic absorption spectrophotometry with gold amalgamation was used for the metal determination. The total mercury average concentration in body feathers was 2.2 ± 1.5 µg.g-1 and 1.3 ± 0.9 µg.g-1 in wing feathers. No correlation was observed between total mercury concentration and the length of body or wing feathers. Total mercury concentration was above 5 µg.g-1 dry weight in only one body feather sample.
Acesso aberto (Open Access)
Interação mutualística entre aves frugívoras de sub-bosque e plantas no Parque Ecológico de Gunma, Santa Bárbara do Pará
(Universidade Federal do Pará, 2008) GOMES, Andreza de Lourdes Souza; JARDIM, Mário Augusto Gonçalves; http://lattes.cnpq.br/9596100367613471; MARCELIANO, Maria Luiza Videira; http://lattes.cnpq.br/4201678009295335
The ingestion of fruits by birds may represent a mutualistic relationship in which they use fruit as nutrient sources keeping intact the seeds. This interaction is described as networks and can present patterns or occurs at random. This study was designed to determine the network structure and the nestedness of interactions between understory bird assemblies and plants from primary and secondary forests at Gunma Ecological Park (PEG), located in the Amazonian region. From March to December of 2007, a total of ten expeditions were conducted for bird capture using mist nets and collection of feces samples for seeds identification. The results were used to determine the connectance, importance index and the nestedness of the mutualistic system. The nestedness in secondary forest was higher than in the primary forest, and the net interaction at Gunma Ecological Park was comprised by 37 species (birds and plants) with connectance of 18% and nestedness of 95%. Birds potentially seed dispersers were represented by 20 species, mainly by the families Pipridae, Tyrannidae, Turdidae and Thaurapidae. Dixiphia pipra was the most important seed disperser species in primary and secondary forest followed by Lipaugus vociferans in primary forest and Cyanerpes caerulens in secondary forest. A total of 17 plants species were found in the diet of birds. Miconia ciliata showed the highest importance index because it interacted with 16 bird species,followed by Phthirusa micrantha in primary forest and Euterpe Oleracea in secondary forest.
Acesso aberto (Open Access)
Natural gaps associated with oxidative stress in Willisornis poecilinotus (Aves: Thamnophilidae) in a tropical forest
(Instituto Nacional de Pesquisas da Amazônia, 2014-06) GOMES, Andreza de Lourdes Souza; GONÇALVES, Andrey Felipe Gomes; VIEIRA, José Luiz Fernandes; MARCELIANO, Maria Luiza Videira; SILVA, José Maria Cardoso da
Natural disturbances in tropical forests modify the availability and quality of resources and alter the patterns of bird distribution. These environmental changes increase the metabolic rate and disrupt the redox balance promoting oxidative stress. This study aimed to compare the abundance of Willisornis poecilinotus between gaps and the understory of a forest with undisturbed canopy at Caxiuanã National Forest. The abundance was correlated with vegetation heights. The oxidative stress and the stress promoting factors were determined in both sites of sampling. We captured 81 specimens of W. poecilinotus. The number of captures was high in gaps. The specimens sampled at gaps showed high levels of oxidative stress. The biomarkers of oxidative stress were significantly correlated in gaps. The variability of oxidative stress and oxidative damage were explained only by site of sampling. These results suggest that gaps are stressors sites to W. poecilinotus, which probably can be due to an increase of metabolic rate to deal with new flight strategies of foraging and avoid predation.
Acesso aberto (Open Access)
Quinine levels in patients with uncomplicated falciparum malaria in the Amazon region of Brazil
(2008-10) VIEIRA, José Luiz Fernandes; BORGES, Larissa Maria Guimarães; NASCIMENTO, Margareth Tavares Silva; GOMES, Andreza de Lourdes Souza
We examined the plasmatic concentrations of quinine in patients with uncomplicated falciparum malaria in an endemic area of the Amazon region in Brazil in a prospective clinical trial, in which a standard three-day course of oral quinine plus doxycycline was used. We measured the quinine in the plasma samples on days 0 and 3by high performance liquid chromatography. The mean concentration of quinine was 6.04 ±2.21 µg/mL in male patients and 5.98 ±1.95 µg/mL in female patients. No significant differences in quinine concentration were observed between these two groups. All samples collected before starting treatment were negative for quinine. This information could help in the development of strategies for the rational use of antimalarial drugs in Brazil.
Acesso aberto (Open Access)
Relationship between plasma and red blood cell concentrations of quinine in Brazilian children with uncomplicated Plasmodium falciparummalaria on oral therapy
(2009-04) VIEIRA, José Luiz Fernandes; GOMES, Andreza de Lourdes Souza; BORGES, Larissa Maria Guimarães; GUIMARÃES, Erika Rodrigues
We determined the relationship between plasma and red blood cell concentrations of quinine in children with uncomplicated falciparum malaria from an endemic area of Amazonian region. Quinine was determined by high performance liquid chromatography with ultraviolet detection. In the steady state the ratio between plasma and red blood cell quinine concentration was 1.89 ± 1.25 ranging from 1.05 to 2.34. This result demonstrated that quinine do not concentrate in red blood cell of Brazilian children and characterize the absence of interracial difference in this relationship.